Folding machine



NOV. 10, 1931. DUNAGlN 1,831,293

FOLDING MACHINE Filed July 18, 1930 2 Sheets-Sheet l K INVENTOR.

(1 H. Dlmagzn 'J {7 Mia ATTORNEY Nov. 10, 1931. G. A. DUNAGIN 1,831,293

FOLDING MACHINE y Filed July 18, 1930 2 Sheets-$heet z INV EN TOR.'

G /l. Du'nagz'n A TTORNEY Patented Nov. 10, 1931 PATENT OFFKIE GEORGEALEXANDER DUN-AGIN, F ATLANTA, GEOBGIA rotnme MACHINE Application filedJuly 18, 1930. Serial No 468,846.

This invention relates to a device for applying adhesive to lettersheets during the folding of the latter to form envelopes of the sheets,the envelopes being sealed so that the contents of the letters cannot beread without breaking the seal. It has for its object the provision ofmeans for applying the adhesive during the folding operation so that theread ing matter will not be obscured and so that the breaking of theseal will not injure the paper to confuse the contents of the letter.The means employed for carrying out the invention are described indetail hereinafter, pointed out in the appended claims, and illustratedby the accompanying drawings.

In the accompanying drawings, in which similar reference charactersdesignate corresponding parts,

Figure 1 shows an elevation of the device for applying the adhesive,with a diagrammatic arrangement of parts of the folding mechanism of thepatent to Nind and Julyan, of December 25, 1906, No. 839,313; only somuch of the patented device being shown as to illustrate the operationof the adhesive applying device.

igure 2 is a detail view, showing the tuck ing blade and the nipplesmounted thereon.

Figure 3 is an enlarged detail view, showing the means for mounting anipple on the tucking-blade.

Figure 4 is a detail perspective view, showing the adhesive reservoirand its mounting.

Figure 5 is a similar view, broken away in part, of a partly foldedsheet.

Figure 6 is adetail sectional view, showing the mounting of a nipple onthe tucking blade.

, Figure 7 is a detail perspective view of the 40 same.

Figure 8 is a detail view, showing ends of the rolls for making thefinal fold.

The device is designed to be mounted on folding machines that are incommon use. Such a machine is disclosed in .Patent No. 839,313, ofDecember 25, 1906, to F. G. Nind and F. Julyan. This patent discloses amachine particularly adapted for folding letter 7 sheets for mailingpurposes. One of the ele- 90 ments of the device of the patent is thetucking blade 94,shown in Figs. 6 and 7 of the patent. The functionof'this'blade is'to tuck the previously folded sheet between the rolls103 and 104 to effect the final fold inthe sheet. The machine of thepatent can be adjusted to. fold a sheet to the form'shown'in Fig. 5 ofthe present application. As shown, the sheet is so. folded that theouter ply a projects at its free edge as at 5 beyond the free edge ofthe adjacent inner ply 0. In the completed folded form of the sheet, thethree plies a, d and e are coextensive, .while the ply 0 is of lesswidth. Thepurpose of the instant inven' tion is to apply to the innerface of the ply e, at the outer corners thereof, as at f, slight daubsof adhesive so that when the final fold. is completed the corners of theply 6 will be pasted to the corners of the ply a clear of the ply 0.When so pasted, the plies will be sealed together so that the readingmatter on'the inner side of the'sheet cannot be read without breakingthe seals. In this the sheet forms the'envelope, which can be addressedfor mailing in the usual manner. As but little paste is used for thedaubs, the seals can be readilybroken by the recipient of the letterwithout injuring the paper to affect the readmg matter. v In the instantinvention, the means for supplying the paste includes a tubularreservoir 1 mounted in a support comprising the base plate 2 and a topplate 3, supported by the bracerods 4 connecting the corners of the twoplates. The support is in the shape of the frustrum of a pyramid toprovide stability. In the top plate 3 is-a central vertical opening inwhich slides the tubular reservoir 1 witha tight fit. By verticallyadjusting the reservoir in the support the elevation of the liquidtherein can be regulated. The bottom of thexreservoir is closed by thestopper 5 fixed therein and the top is provided with the'removablestopper 6 so that the adhesive'can be" poured into the reservoir.Communicating with the interior of the reservoir and leading throughthe'lbot tom thereof 'is the pipe 7, provided with the. controllingvalve '8. Connected .with" the. outer end of the pipe is the flexibletubing 9, branched at its outer end. At the extremity of each branch ofthe tubing is the nipple 10. Extending through the bottom of thereservoir and communicating with the upper part thereof is the air-inlettube 11, provided at its outer end with the valve 12 to regulate theadmission of air into the reservoir as the adhesive is withdrawn.

The tucking-blade 94 of the present invention corresponds to thetucking-blade 94 of the patent, supra, and in the folding operation itsfunction is the same. The structure of the blade is modified somewhat tocoact with the device for applying the adhesive. In the opposite ends ofthe blade 94 are the vertical slots 13 extending upward through theblade. On the back of the blade and over each slot 13 thereinextends theguide 14 having in its rear side a slot 15 coinciding with the slot 13In each guide is slidable a block 16 of elastic material, such as arubber composition, compressed therein. The block can be adjusted alongthe guide and is frictionally held in its adjustments. Extending througheach block 16 is one of the nipples 10 with its discharge openingprojecting through the adjacent vertical slot 13, slightly in advance ofthe blade 94. The rear end of the nipple extends through the slot 15 inthe adjacent guide and is connected with one of the branches of theflexible tubing 9, leading from the adhesive reservoir. The nipples havea tight fit in their respective blocks 16 and can be adjusted therein toproject more or less from the face of the tucking blade to meetdifferent requirements; also, thenipples can be entirely withdrawn fromthe blocks should it be desirable to operate the machine without theapplication of the adhesive.

In the operation of the device, the adhesive reservoir with its mountingis supported adjacent to the folding machine, the reservoir beingelevated above the nipples 10 mounted in the tucking-blade 94 so thattheadhesive can flow by gravity through the connection between thereservoir and the nippics. The mechanism of the folding ma chine isadjusted so that the first fold in a letter sheet will form plies ofunequal length to provide the marginal part I) in the ply a-d. After thefirst fold is formed by the rolls 47 and 54 (ofthe patent), the foldedsheet is carried by the tapes 74 and thecooperating guides 113 to aposition between the tucking-blade 94 and the coacting rolls 103-104..Inthis position, the creased edge of the folded sheet restson the pins117 and with the ply a-cZ abutting the rolls 103-104. So positioned, thelower corners of the ply 0-6 are directly opposite to the nipples 10carried by the tucking blade. As the blade oscillates to tuck the sheetbetween the rolls 103-104 for the final fold, the nipples are forcedlightly against the lower corners of the ply c-e, as at f, and a daub ofthe adhesive is applied. The oscillation of the blade in the tuckingoperation is Very quick and there is only a momentary contact of thenipples with the paper and but slight daubs of the adhesive are applied.After the tucking operation of the blade, the rolls 103-104 complete thefinal fold of the sheet. As the folded sheet passes between these rolls,the corners of the ply e are pressed into contact with the corners ofthe marginal partb of the ply aso that the daubs of adhesive at f sealtogether the two plies a and d. s the adhesive is applied to the ply ein close proximity to the crease between this ply and the ply cl, thelatter is practically sealed to the ply a.

When the blade 94 tucks the assembled plies between the rolls 103-104,the lower part of the plies is moved upward to accommodate the tuckingmovement. Advantage is taken of this upward movement of the lower partof the plies to provide elongated daubs of the adhesive along the inneredges of the ply to seal the ends of the envelope. To accomplish thispurpose, the nipples 10 are adjusted to the upper parts of the guides14, so that a considerable part of the ply 0 extends belowthe nipples.By adjusting the nipples longitudinally in the blocks 16, their proection toward the folded sheet can be regulated. When the ply is movedupward in the tucking operation, its inner ends are wiped across thenipples so that narrow streaks of adhesive are applied to the inner endsof the ply parallel to its edges. \Vhen the folded sheet, so prepared,passes between the rolls 103-104, the inner ends of the plies 0 and 6,together with the corners of the margin Z) are pressed together and theentire ends of the envelope are sealed together. F or some purposes, theends of the ply 0 may be cut away, as indicated by the dotted lines It,so that the ends of the ply 6 will be sealed directly to the ply "a. Inthis way, should either method of sealing be employed, the letter sheetis formed into a sealed envelope, ready for niailing, and which can beeasily opened by the-recipient without damaging the paper to confuse thereading matter.

In applying pressure to the plies, the rolls 103-104 do not act directlyon those parts of the plies to which the plied. In the ends of theserolls are annular grooves, as at lT Fig. 8, which register with eachother and track the travel of the daubs f, appliedin spots or elongatedstreaks, so that there will be no direct application of pressure bythe'rolls to squeeze the adhesive from between the plies to smear therolls or to cause the stacked letters to adhere to each other. Duringthe folding of the sheet and as its lower part moves upward, the daubs fthereon travel opposite the slots 13 and cannot contact with thetucking-blade to foul the same.

adhesive has been ap- The supply of the adhesive from the reservoir 1can be readily requirements. lVhen the machine'is set in operation, thecocks 8 and 12 are opened the former to permit the flow of adhesive romthe reservoir through the flexible tubing 9 to the nipples 10 and thecock 12 to admit air through the pipe 11 to replace the adhesive as itflows from the reservoir. Also, by vertically adjusting the reservoir inthe top plate 3 of the support, the liquid can be mantainedapproximately at a constant head to insure a uniform flow of theadhesive as its level lowers in the reservoir. The fluidity of theadhesive depends on its composition, temperature and other conditions;by means of the several adjustable controls, the device can be regulatedto accommodate the fluidity of the adhesive so that the required flow atthe nipples can be secured to provide the necessary daubs. By adjustingthe blocks 16 in their guides, the nipples can be positioned toaccommodate sheets of difierent length and of different folds. While twonipples have been shown, it is apparent that additional ones can beemployed by providing additional mountings on the tucking-blade andproviding additional branches to the flexible tubing.

What I claim is 1. In a folding machine, the combination of a movableelement operative to engage a sheet preliminary to a subsequent foldingof the sheet, with a source of and a nipple communicating with thesource of adhesive and mounted in the movable element to apply a daub ofthe adhesive to the sheet when the element is moved to engage the sheet.

2. In a folding machine, the combination of a movable element operativeto engage a sheet preliminary to a subsequent folding of the sheet, witha guide on the element, a nipple adjustable in the guide, and a sourceof liquid adhesive communicating with the nipple, the nipple operatingto apply a daub of the adhesive to the sheet when the element is movedto engage the sheet.

3. In a folding machine, the combination of a movable blade operative toengage a sheet preliminary to a subsequent folding of the sheet, theblade having an elongated slot therein, with a guide on the bladeextendingan elastic block slidable in the guide, a nipple mounted in theblock to extend through the slot in the blade, and a source of liquidadhesive communicating with the nipple, the nipple operating to apply adaub of the adhesive to the sheet when the blade is moved to engage thesheet, and the sliding of the block in the guide operating to vary theposition of the nipple to accommodate sheets and plies of differentdimensions.

4. In a folding machine, the combination over the slot therein,

controlled to meet the iquid adhesive, 7

of amovable element operative'to engage a sheet preliminary to asubsequent folding of the sheet, with a nipple mounted in the movableelement to contact with the sheet when the element is moved to engagethe sheet, a support, a reservoir for liquid adhesive mounted in thesupport above the nipple, a flexible connection between the lower partof the reservoir and thenipple so that the nipple on contact with thesheet applies a daub of adhesive to the sheet when the element is movedto engage thesheet, and meansfor controlling the" flow of adhesive fromthe reservoir to the nipple.

5. In a folding machine, the col bination of a movable element operativeto engage a sheet preliminary to a subsequent folding of the sheet, witha nipple mounted in the movable element to contact with the sheet whenthe element is moved to engage the sheet, a support, a reservoir forliquid adhesive vertically adjustable in the support above the nipple, aflexible connection between the lower part'of the reservoir and thenipple so that the nipple on contact with the sheet applies a daub ofadhesive to the sheet when the element is moved to engage the sheet, thevertical adjustment of the reservoir in the support operating toregulate the pressure of the adhesive flowing from the reservoir to thenipple, and means controlling the flow of the adhesive from thereservoir through the flexible connection. v

6. In a folding machine, the combination of a movable element operativeto engage a sheet preliminary to a subsequent folding of the sheet, witha source of liquid adhesive, and a nipple communicating with the sourceof adhesive and mounted to project in advance of the element to contactwith the engaged sheet to apply a daub of adhesive thereto as the sheetis moved by the element 'ing of the sheet, the adjustable mounting beingoperative to position the nipple to provide an extended contact of thenipple with the sheet as the sheet is moved by the ele-' ment in thesubsequent folding of the sheet.

8. In a folding machine, the combination of a movable element operativeto engage a sheet preliminary to a subsequent folding of the sheet, witha source of liquid adhesive, a nipple communicating with the source ofadhesive, and adjustable means for mounting the nipple on the element toprojectthe nipple in advance of the element to contact with the engagedsheet to apply a daub of adhesive thereto as the sheet is moved by theelement inthe subsequent folding of the sheet, the adjustable meansbeing operable to pro-: vide a variable contact of the nipple with thesheet.

9. In a folding machine, the combination of coacting folding rolls, oneof the rolls having an annular groove, with a tucking blade operative totuck a sheet between the rolls, and means for applying a daub ofadhesive to the sheet in a position to register with the annular grooveas the sheet travels between the rolls, the daub being applied to theinner face of one of the plies of the sheet so that when the two pliesformed by the rolls are brought together the daub will be pressedbetween the two plies to form an adhesion therebetween.

10. In a folding machine, the combination with a source of liquidadhesive, of a nipple communicating with the source of liquid adhesive,and means for folding a sheet into plies, said means operating initiallyto move a ply of the sheet to contact with the nipple to receivetherefrom a daub of adhesive, the subsequent folding of the sheet bysaid means pressing the ply with the daub against the adjacent ply inthe completed fold.

In testimony whereof I afiix my signature.

GEORGE ALEXANDER DUNAGIN.

